Abstract
In adult mammals, HSCs reside in the bone marrow (BM) cavity near diverse groups of stromal cells, which maintain the structural integrity of both bone and marrow microenvironments. Interactions among stromal cells and hematopoietic stem and progenitor cells modulate many of the critical functions of the hematopoietic system, including production of specific blood lineages and responses to infection and inflammation. Our understanding of these interactions has grown considerably with application of new technologies that have uncovered how cell populations associate in situ and exchange molecular signals. We will describe important architectural features of the BM cavity and its cellular composition and explore the central role of mesenchymal stromal cells (MSC) as organizers of hematopoietic niches.
